Fuse



Jan. 7, 1958 sHENK 2,818,812

FUSE

Filed Oct. 14, 1952 2 Sheets-Sheet 1 Fig 1- i I FIE- lil- INVENTOR.Dmnuld I-l- Ehenk BY w zzmwuwm ATTORNEYS D. H. SHENK FUSE 2 Sheets-Sheet2 Filed Oct. 14, 1952 .k wvulv 11.4% L I i m TOR. 7

Enk.

25 INV Donald H.

FUSE

Donald H. Shenlr, Huntsville, Ala,- assignor to the United States ofAmerica as represented 'by-the Secretary of the Army Application October14, 1952, Serial No. 314,757

4 Claims. (Cl. 102'-79) (Granted under Title 35, U. s. Code (1952), sec.266) The invention described herein may be manufactured and used by orfor the Government for governmental purposes without the payment to meof any royalty thereon.

This invention relates to improvement in fuses.

An object of the invention is to provide a fuse which cannot bedetonated in its unarmed position.

Another object of the invention is to provide a fuse which is bore safe.

Another object of the invention is to provide a fuse which will be safeto handle at the end of its flight if the control arms fail to function.

A further object of the invention is to provide a fuse designed forpoint or graze detonation.

A still further object of the invention is to provide a fuse which willdetonate at the end of its flight regardless of whether it strikes atarget or not.

A still further object of the invention is to provide a fuse havingdelayed firing means.

A still further object of the invention is to provide a fuse which issimple in construction and requires a minimum of machining.

Other objects and advantages will-be apparent from the followingdetailed description and the accompanying drawings, in which:

Figure 1 is a central longitudinal section of a portion of a projectileequipped with a fuse illustrating the present lnvention;

Figure 2 is a longitudinal section of the line 22 of Figure 1;

Figure 3 is a transverse section on the line 33 of Figure 1;

Figure 4 is a transverse section on the line 44 of Figure 1;

Figure 5 is a transverse section on the line 55 of Figure 1;

Figure 6 'is a central longitudinal section of a projectile equippedwith a fuse illustrating a slightly modified form of the presentinvention;

Figure 7 is a longitudinal section on the line 77 of Figure 6;

Figure 8 is a transverse section on the line 8-8 of Figure 6;

Figure 9 is a transverse section on the line 9-9 of Figure 6.

In the drawings, wherein for the purpose of illustration, is shown twoforms of the invention, the reference chara'c'2ters 1t) and 10a indicateany form of rotating projectile having a bursting charge 11 and 11arespectively.

Referring'now to Figures 1 through 5. Secured to the projectile by anypreferred means, such as-screw threads 12, is a fuse 13. A body portion14 is cast or machined to provide a tip 15 and a base 16. Extendingaxially through the body portion from the base 16 to a point near thetip 15 is a bore 17, for receiving a detonator or primer 1% in the innerend thereof.

,t,8l2 Patented Jan. '7, 1958 The outer end of the bore slidablyreceives a'firing'pin 19'and its propelling spring 20. The inner end'21of the firing pin is reduced in diameter-"for striking the detonator 18.

Intermediate the inner end 21 of the firing pin and the detonator 18 atransverse slot 22 is formed. The side walls of the slot are grooved toform guide'ways 23 for a barrier member 24 shaped on its edges toslidably lit the guideways. A light spring 25 is seated at its inner endin a socket 26 in the barrier member and at its outer end bears againstthe wall "of a windshield 28. The windshield envelops the fuse bodyportion for the usualpurpose.

The barrier member-is normally urged inwardly against shoulders 29 whichform the ends of guideways 23' to properly center the barrier member. Aseat or indentation 30 is formed in the forward face of the barriermemher in axial alignment with the reduced end 21 of the firing pin.Normally thefiring pin point 21 rests in' the seat 30 and retains thebarrier in safe position.

In rotational flight the barrier member will be held against movement bythe firing pin until such time as it is released as will be hereinafterdisclosed. The barrier member 24 will move outwardly compressing itsspring 25 and uncovering the bore 17. A detent 31, square incross-section and urged forwardly by a spring 32, is slidably receivedin a slot 33 in the base 16 of thebody portion. A notch 34 formed in therearward-face of the barrier is positioned to receive thedetent and holdthe barrier retracted.

In practice the use of a very light spring 25 is contemplatedandtherefore the detent 31 may be found unnecessary. In which event onimpact the residual forces in the barrier 24 will hold it retracted longenough for the firing pin to snap into the detonator 18.

Radial slots'35 are formed in the body portion to receive control arms36. While two arms are shown in the model illustrated, three or more maybe used if desired. Each control arm is mountedto oscillate in itsradial slot on a pivot pin 37, secured in the'body portion. As thecontrol arms are identical 3. description of one will sufiice for both.

The control arm'36 has a weighted end 38 which is outwardlydisposed'with respect to the' aXis of the fuse body and to its other end39, and forwardly with respect to its pivot pin, for reasons which willbe more fully explained. The inner end of the firing pin 19 has formedthereon a shoulder 40 which is normally engaged by an inturned toe 41formed on the short rearward end 39 of the control arm.

A latch 4-2 provided with a pivot element 43 is rotatably received in abore-in the body portion. Adjacent thelatch and the short end of thecontrol arm the body portion is cut out to provide a recess Mam-man "thelatch may turn. The freeend of the latch is formed with a flat face 45which engages the abutting face of the short end 39 of the control armwhereby movement of the latch is restrained untilsuflicient-spin'isgenera tedto move theoifset'end 38 of control arm outwardly.

The operation of the "invention is as follows:

-In unarmed condition the spring loaded-"firing p'in'19 is restrained bythe barrier member 24 which normally closes the bore 17. The end 21 ofthe firingpin engages the seat 30 and renders the fuse safe.

As herein before stated the center of gravity of each control arm 36 islocated forwardly of its pivot axis and in the position of the armsshown up'on Figure l-is radially and outwardly offset from thelongitudinal planes through the axes of the respective shafts 37, sothat centrifugal force and the forces of set-back both tend to holdthefiring pin safe, that is, in the position of Figure 1, when fired.

When the ends 38 of the control arms move outwardly, consequently theinner ends 39 are moved inwardly and the firing pin point is cammedforwardly away from the barrier member. Continued and increasedrotational forces cause the ends 38 of the control arms to move fartheroutward until the latches 42 are free and rotate under centrifugalforce, out of contact with the short ends 39 of the control arms. Thebarrier member 24 also moves outwardly under centrifugal force of thespinning projectile and is held in outward armed position when detent 31snaps into recess 34. Thus, in flight, the firing pin is restrained onlyby the toe 41 of the control arm.

On point impact the sudden deceleration causes the ends 38 of thecontrol arms to move forwardly and inwardly to release the firing pinbut the firing pin also moves forwardly from inertia forces causing adelay in firing. The slight delay occasioned by the forward movement ofthe firing pin allows the projectile to penetrate a short distance intothe target before detonation occurs.

When graze impact occurs the resulting deceleration pivots the controlarms sufiiciently to release the firing pin and almost instantaneousdetonation occurs, thus causing some damage when the impact is tooobtuse for penetration of the target.

In case no target is hit, the decay of spin plus the inertla dragforward on the control arms enables the conical end of pin 19, under thethrust of spring 20, to cam the rearward ends of the arms outwardlyuntil the pin is released and driven into the primer to detonate thecharge.

Figures 6 through 9 illustrate a modified form of the invention whereinlike parts are designated by like reference characters with the additionof the sufiix a.

Secured to the projectile by any preferred means, such as screw threads12a, is a fuse 13a. A body portion 14a is cast or machined to provide atip 15a and a base 16a. Extending axially through the body portion fromthe base 16a to a point near the tip 15a is a bore 17a, for receiving adetonator or primer 18a in the inner end thereof.

The outer end of the bore slidably receives a firing pin 19a and itspropelling spring 20a. The inner end 21a of the firing pin is reduced indiameter for striking the detonator 18a.

Intermediate the inner end 21a of the firing pin and the detonator 18a atransverse slot 22a is formed. The side walls of the slot are grooved toform guideways 23a for a barrier member 24a shaped on its edges toslidably fit the guideways. A light spring 25a is seated at its innerend in a socket 26a in the barrier member and at its outer end bearsagainst the wall of a windshield 28a.

The barrier member is normally urged inwardly against shoulders 29awhich form the ends of guideways 23a to properly center the barriermember. A seat or indentation 30a is formed in the forward face of thebarrier member in axial alignment with the reduced end 21a of the firingpin. Normally the firing pin point rests in the seat 30a and retains thebarrier in safe position.

In rotational flight the barrier member will be held against movement bythe firing pin until such time as it is released as will be hereinafterdisclosed. The barrier member 24a will move outwardly under centrifugalforce, thus compressing its spring 25a and uncovering the bore 17a.

Radial slots 35a are formed in the body portion to receive control arms36a. Each control arm is mounted to oscillate in its radial slot on apivot pin 37a, secured in the body portion. As the control arms areidentical a description of one will suffice.

In this form of the invention, as is indicated by dotted lines uponFigure 6, the control arm 36a, in a normal or unarmed condition, is freeto oscillate about its pivot pin within the limitations of a shoulder40a on the firing pin and the body portion of the firing pin 19g.Consequently one or more of the control arms will be in contact with theshoulder 40a, regardless of the position of the fuse, more certain witha multiplicity of control arms.

The control arm has a weighted end 38a which is disposed forwardly ofits pivot pin and outwardly of the rotating axis of the fuse body, forreasons which have been set forth.

At its inner end 39a, the control arm is disposed rearwardly of itspivot pin and inwardly thereof for engaging the shoulder 40a of thefiring pin.

At the height of acceleration in the barrel, the outward movement of thecontrol arms is limited by stops 47.

The firing pin is formed with a reduced extension 46 extending apredetermined distance forwardly in the bore 17a, and adapted to limitthe forward movement of the firing pin on impact to control the time ofdelayed firing.

The operation of the modified form of the invention is as follows:

In unarmed condition the spring loaded firing pin 19a is restrained bythe barrier member 24a which normally closes the bore 17a. The end 21aof the firing pin engages the seat 30a and renders the fuse safe.

In this modification of the invention the control arms 36a are notrestrained by latches 42 as shown in Figure 1. The control arms assume aposition in contact with the shoulder 40a of the firing pin on set-back,due to their weight distribution as hereinbefore stated. The barriermember cannot be retracted until sufiicient centrifugal force has beengenerated in fl ght, to cause the control arms to cam the firing pininto release position.

As the high rate of spin of the projectile during flight moves theweighted ends of the control arms outwardly the firing pin spring isfurther compressed and held until the fuse contacts a target.

On impact with a target the control arms move inwardly and the firingpin moves forwardly to cause delayed firing in the same manner as setforth in the previous description of the first form of the invention.

The operation of this form of the invention on graze impact and on decayof spin is also identical with that of the first form.

While I have disclosed two forms of the present invention presentlypreferred by me, various changes and modifications will occur to thoseskilled in the art after a study of the present disclosure. Hence thedisclosure is to be taken in an illustrative rather than a limitingsense; and it is my desire and intention to reserve all modificationsfalling within the scope of the subjoined claims.

Having now fully disclosed the invention, what I claim and desire tosecure by Letters Patent is:

1. In a fuse of the type described, a fuse body having a firstlongitudinal axis of symmetry and a bore coaxial with said axis, therebeing a slot in said body transversely of and intersecting said borebetween the ends thereof, a firing pin slidably fitting said bore, abarrier member slidably fitting said slot and movable in response tocentrifugal force from a first position obstructing said bore to asecond position free of said bore, first spring means urging said memberinto first position, second spring means urging said firing pinrearwardly into position engaging a recess in said member when in firstposition to hold the same against movement, a control arm pivotedintermediate its ends within said body for movement about a second axisnormal to and laterally offset from said longitudinal axis, the centroidof said arm being forward and radially outward of said second axis, alatch member pivotally mounted on an axis parallel with the said firstlongitudinal axis normally engaging the rear end of said control arm andresponsive to centrifugal force to remove from said normal engagement tofree the said control arm for said movement about said second axiswhereby upon such movement the rearward end thereof engages said pin andmoves the same forwardly to release said barrier member.

2. In a fuse of the type described a fuse body having a firstlongitudinal axis of symmetry and a bore coaxial with said axis, therebeing a slot in said body transversely of and intersecting said borebetween the ends thereof, a firing pin slidably fitting said bore, abarrier member slidably fitting said slot and movable in response tocentrifugal force from a first position obstructing said bore to asecond position free of said bore, first spring means urging said memberinto first position, second spring means urging said firing pinrearwardly into position engaging a recess in said member when in firstposition to hold the same against movement, a plurality of control armswithin said body and equiangularly spaced about said first longitudinalaxis, each said control arm pivoted intermediate its ends for movementabout a second axis normal to and laterally offset from said firstlongitudinal axis, the centroid of each said arm being forward andradially outward of said second axis, a plurality of latch memberswithin said body, one for each said control arm, and pivotally mountedon an axis parallel with the said first longitudinal axis, each saidmember normally engaging its respective control arm and responsive tocentrifugal force to remove from said normal engagement to free the saidcontrol arms for said movement whereby the rearward end thereof engagessaid pin and moves the same forwardly to release said barrier member.

3. In a fuze of the type described a fuze body having a firstlongitudinal axis of symmetry and a bore coaxial with said axis, adetonator seated in the rear end of said bore, a firing pin slidablyfitted in said bore and spaced from the forward end thereof in normalsafe position, there being a slot in said body transversely of andintersecting said bore between the rearward end of said firing pin andsaid detonator, a barrier member having a seat formed in its forwardface for receiving the rearward end of said firing pin and beingslidably fitted in said slot and movable in response to centrifugalforce from a first position closing said bore to a second positionopening said bore, first spring means urging said member into firstposition, second spring means in the forward end of said coaxial boreurging said firing pin rearwardly into position engaging said seatholding said member in first position, a plurality of centrifugallyoperated control arms within said body and equiangularly spaced aboutsaid first longitudinal axis, each said control arm pivoted intermediateits ends for movement about a second axis normal to and laterally olfsetfrom said first longitudinal axis, the mass center of each said armbeing forward and radially outward of said second axis, a plurality oflatch members within said body, one for each said control arm, andpivotally mounted on a third axis parallel with said first longitudinalaxis, each said member normally engaging its respective control arm andresponsive to centrifugal force pivots about said third axis from saidnormal engagement to free said control arms for said movement wherebythe rearward end thereof moves said pin forwardly to release saidbarrier member.

4. In a fuze of the type described a fuze body having a firstlongitudinal axis of symmetry and a bore coaxial with said axis theforward end thereof being closed to provide a delay action chamber, afiring pin slidably fitted in said bore and spaced from the forward endthereof in normal safe position, a detonator seated in the rear end ofsaid bore, there being a slot in said body transversely of andintersecting said bore between the rearward end of said firing pin andsaid detonator, a barrier member having a seat formed in its forwardface for receiving the rearward end of said firing pin in normal safeposition, said member being slidably fitted in said slot and movable inresponse to centrifugal force from a first safe position closing saidbore to a second position opening said bore, first spring means urgingsaid member into first safe position, second spring means in said delayaction chamber urging said firing pin rearwardly into position engagingsaid seat to lock said member in first safe position, a plurality ofcentrifugally operated control arms within said body and equiangularlyspaced about said first longitudinal axis, each said control arm pivotedintermediate its ends for movement about a second axis normal to andlaterally offset from said first longitudinal axis, the mass center ofeach said arm being forward and radially outward of said second axis, aplurality of latch members within said body, one for each said controlarm, and pivotally mounted on a third axis parallel with said firstlongitudinal axis, each said member nor mally engaging its respectivecontrol arm and responsive to centrifugal force to pivot about saidthird axis from said normal engagement to free said control arms forsaid movement whereby the rearward end thereof moves said pin forwardlyto release said barrier member for outward movement under the influenceof centrifugal force, and forces said pin into said delay action chamberagainst the bias of said second spring, said second spring being capableof further compression in said chamber on impact to effect a delayfiring period.

References Cited in the file of this patent UNITED STATES PATENTS1,955,779 Teitscheid Apr. 24, 1934 2,014,393 Mathsen Sept. 17, 19352,641,186 Apotheloz June 9, 1953 FOREIGN PATENTS 891,266 France Nov. 29,1943 928,644 France June 9, 1947

